1. Field of the Invention
The invention relates to color cathode ray tubes having an apertured member within the display panel and more particularly to improved internally positioned means for dampening vibrations of the apertured member.
2. Description of the Prior Art
The progressive advancement of color television receiver art is manifest in both the video and audio portions of the equipment. Recent improvements in the sound circuitry have incorporated stereo and wide range audio responses into the receiver. While such improvements achieve enhanced realism in audio reproduction, some related video problems have occurred in certain receiver cabinet environments. For example, there are instances in which low frequency vibrations emanating from the bass speakers are physically transferred through elements of the cabinet structure to the color cathode ray tube component. Such sound-induced vibrations can cause deleterious movement of the shadow mask-frame assembly suspensionally-mounted on the sidewall of the display panel, in turn causing misregistration of the electron beams impinging on the patterned display screen, and degradation of picture quality.
To counteract these vibration-induced "microphonics", a plurality of suppression or dampening means have been added to the shadow mask frame assembly of the CRT as disclosed by Carl W. Penird and Richard A. Tamburrino in U.S. Pat. No. 4,318,025. Such suppressors are formed of spring-like material and attached to the ledge of the mask framing member and extended therefrom in a manner to make contact with the adjacent sidewall of the display panel, thereby effecting dampening of the audio-induced vibrations of the shadow mask-frame assembly. In some instances, the extensive bent-leg formations of the suppressors allows a degree of reverberation which detracts from the intended dampening effect of the suppressors. Such is especially noticeable when the extra mass of an internal shielding member is attached to the frame portion of the mask-frame assembly.